The supply of many valuable proteins that have potential clinical or industrial use is often limited by their low natural availability. With the modern advances in genomics, proteomics and bioinformatics, the number of proteins being produced using recombinant techniques is exponentially increasing and seems to guarantee an unlimited supply of recombinant proteins. However, the soluble expression of heterologous proteins in E. coli remains a serious bottleneck in protein production. Overexpression of cloned genes in E. coli may lead to the formation of intracellular proteinaceous granules that are readily visible under the light microscope. A number of parameters relating to the host cell, the growth conditions and the properties of the particular protein affect this process. Therefore, new technologies to enhance protein expression and simplify the purification process are needed to help protein investigation at the scale of many proteins simultaneously.